Sarajevo: Four Bosnians and a Swede of Arab origin were arrested in Bosnia after being found with an explosive device to be used for "a terrorist act" in a Scandinavian country, police said Friday.

The operation, coded "Benelux," was carried out by Bosnian, Swedish and Dutch police, Bosnian police said in a statement.

"These persons are suspected to have produced an explosive device in Bosnia with the intention of delivering it in a Scandinavian country," it said said.

"The device was supposed to be used for a terrorist act."

Last month, a gunman of Palestinian origin killed two people in Copenhagen.

The authorities refused to give further details, including the final destination or specify if the suspects were linked to local Islamist movements.

In a separate statement, a prosecutor said the Swedish citizen was "of Arab origin."

Three suspects were arrested as they were trying to leave Bosnia in a car where the device was found, police said, adding that another two were arrested in the capital Sarajevo.

Forty percent of Bosnia`s 3.8 million inhabitants are Muslim.

According to Bosnian intelligence estimates, some 150 citizens are currently fighting along with jihadist groups in Iraq and Syria and some 20 have been killed so far. Some 50 other jihadists returned to Bosnia.